John doherty



(No Model.)

J. DOHERTY. VALVE GEAR FOR PUMPS.

No. 606,480. Patented June28,1898.

VIII/III 4 TIGZ.

W/ TNE SSE S J /NVENTO/? ATTOHNE NlTED STATES i ATENT Wren.

JOHN DOHER'IY, OF LOOKPQRT, NEW YORK.

VALVE-GEAR FOR PUMPS.

SPECIFICATION forming part of Letters latnt No. 606,480, dated June 28, 1898. Application filed December29, 1397. f Serial No. 664,278. (No model.)

To (0% whom it may concern: 1 Be it known that I, JOHN DOHERTY,Of Lock: port, in the county of Niagara and State of New York,have invented a new and Improved Valve Gear for Pumps, of which the following is a full, clear, and exact description."

This invention relates to an improvement in valve-gears for pumps, and is especially adapted for use with single pumps; and it consists of certain novel features, which will be hereinafter described and claimed.

Reference is to be had to the accompanying drawings, forming apart of this specification, in which similar characters of reference indicate corresponding parts in all the views.

Figure 1 is a side elevation, partially in section, of a pump with my valve-gear attached thereto. Fig. 2 is a longitudinal sectional elevation of the steam-cylinder of a pump and my valve-gear thereon shown in a different position from that of Fig. 1. Fig. 3 is a sec. tional end elevation between the valve-gear and the water-cylinder,'and Fig. 4 is a detail view showing a modified construction for th pivoted dog.

In the drawings my valve-gear is shown as applied to a singlepump, in which A represents the steam-cylinder; a, the steam-piston A, the valve-chest; A the water-cylinder, and B the valve. These parts maybe of any ordinary or desired construction, as the parstruction is a preferred one for connecting the lever D to the pump-rod C, but is not 68-.

sential, as any desired form of connection may be used. The lever D is pivoted at e to the connectingportion A of the frame, extending between the steam and water cylinders. The upper end of the lever D is forked,

forming two arms D, each of which is pro- .vided with a set-screw d, the use of which will be hereinafter described.

A dog or lever E is pivotedto the frame A, preferably upon the same pivot asthat of the leverD, although this is. not strictly essential. This dog has its outer end formed with sloping edges or diamond-shaped, the edges E thereof acting as cam-surfaces. The dog E is also provided with a lateral slot E adapt: ed to receive a pin 1), which is carried by the yoke b. This yoke is connected to the valvestem either by a rigid connection, as shown in the drawings, or by a pivoted connection, as may be desired. The lever D and'dog E thus form a compound lever formed in two sections which are pivoted to each other. By means of the arms D and the set-screws (Z the amount of slack between these two sect'io'ns may be adjusted at will.

.Upon guides A extending upwardly from the frame, is mounted a cylinder F, and within thiscylinder is a plunger or piston F, to the lower end of which is pivoted a roller 'F by a' pin f. The "lower, end of the plunger F is formed as a yoke F which embraces the roller F and the upper end of the dog E. .To the upper end of the plunger F is fixed a packing ring or plate F whichis of leather or other suitable material which will form a tight joint for the plunger and prevent leakage of steam. The upper end of the cylinder F is connected by pipes G with .the steam- Q toward the steam-chest to guard against throttling of the steam as the sameis driven out of the cylinder F by the plunger rising. As shown in detail in Fig. 4, the dog E may be provided with two plates I, which are secured by a clamping-bolt I to one side of the dog E. These plates are provided with slots 1, adapted to embrace the clamping-bolt. One end of these plates extends over the slot E By means of these plates the length of the slot may be reduced and the amount of slack or lost motion. between the dogEand the valve-stem may be regulated. r The plates I, in fact, may be adjusted so as to entirely do away with this lost motion. y this means the valve may be regulated so as to cutoff the admission of steam before the piston has completed its stroke.

The operation" of my device is as follows: WVith the parts in the position shown in ,Fig. 2, steam is being admitted to the left of the piston, which will force the piston to the right. As it moves in this direction it will swing the lever D, and this will raise the dog E. The cam-surfaces E of the dog engaging the roller F will raise the plunger F until it is resting upon the point of the dog. This will be the position of the dog and plunger shown in Fig. 1, although the lever D will be in a diiferent-position from the one shown therein. Any further movement of the piston to the right will swing the dog to the left a sufficient distance, so that the steam-pressure upon the plunger F will force the same downward, and by engagement of the roller F with one of the cam-surfaces E will throw the dog E to the left. The previous movement of the dog has not moved the valve by reason of the extent of the slot E in the dog. Further movement of the dog will, however, throw the valve toward the left, so as to admit steam to the opposite side of the piston. This latter movement will be a quick one and will insure a full opening of the valve. The steam being admitted to the opposite side of the piston will then force it in the opposite direction. The same operation of the parts will occur until the parts reach the position shown in Fig. 1. A further movement of the piston to the left will result in the dog E being forced to the right by the pressure of the roller F thereon. It will thus be seen that the movement of the valve is not caused directly by the movement of the pump piston and rods. These, however, indirectly cause the movement of the valve by moving the dog E into position where it will be thrown by the plunger F. The actual movement of the valve, itwill be seen, is caused directly by steam-pressure. In consequence the movement of the valve is a positive one independent of the speed of motion of the pump, and is one quickly accomplished.

This form of valve-gear will thus enable a pump to be run at as slow a speed as desired without any probability of the pump stopping, and in cases where such operation is desired the pump may be stopped for any length of time and will promptly resume operations as soon as the pressure against which the pump is operating is sufficiently reduced.

Having thus described my invention, I claim as new and desire to secure by Letters Patent- 1. A pump valve-gear, comprising a pivoted dog having its outer edge faces inclined toward each other and forming cam-surfaces, a roller mounted to slide toward and from the pivot of said dog and engaging said cam-surfaces, a-pivoted lever having vibratory connections to the pump-piston and having arms adapted to engage opposite sides'ot' the dog, to'vibrate it, but being wider than the dog so as to have lost motion between the two, and connections from said dog to the steam-Valve, substantially as described.

2. Apump valve-gear, comprising a pivoted dog or lever having its outer end pointed or diamondshaped, and a laterally-extending slot therein, a valve-operating rod having a pin extending into said slot, a roller mounted to slide toward and from the pivot of said dog and bearing upon its inclined edges, a pivoted lever having vibrating connection with the pump piston-rod, and arms upon said lever adapted to embrace the dog, to vijorate it, substantially as described.

3. A pump valve-gear, comprising a pivoted dog or lever having its outer end pointed or diamond-shaped and a laterally-extending slot therein, a valve-operating rod having a pin extending into said slot, a cylinder and plunger mounted in line with the pivot of the dog, connections from the cylinder to the steam-supply for the pump, a plunger having a roller engaging the inclined surfaces of the dog, a pivoted lever having vibrating connection with the pump piston-rod, and arms upon said lever adapted to embrace the dog, to vibrate it, substantially as described.

4.. Apump valve-gear, comprising a pivoted dog or lever having its outer end pointed or diamond-shaped and forming inclined caulsurfac'es and also having a laterally-extendin g slot therein, a valve-operating rod having a pin extending into said slot, a cylinder or plunger mounted in line with the pivot of the dog, connections from said cylinder to the steam-supply for the pump, a throttling-valve in said steam connection, a by-pass having a check-valve opening toward the steam-supply, a roller mounted upon the plunger and engaging the cam-surfaces of the dog, and a pivoted lever having vibrating connection with the pump piston-rod and arms adapted to embrace the dog, to vibrate it, substantially as described.

5. A pump valve-gear, eomprisin g a pivoted dog or lever having its outer end pointed or diamond-shaped and forming inclined camsurfaces, connections therefrom to the steamvalve, a yielding plunger having a roller hearing upon the cam-surfaces of the dog and toward its pivot, a pivoted lever having vibratory connection with the pump-rod and having arms embracing the dog, and set-screws extending through said arms whereby the slack or lost motion between the arms and the dog may be regulated, substantially as described.

6. A pump valve-gear, comprisinga pivoted dog or lever having its outer end pointed or diamond-shaped and forming inclined camsurfaces, said dog having a lateral slot, adjustable plates by which the extent of said slot may be regulated, a valve-stem connection to said slot comprising a pin entering saicl slot, a yielding plunger having a roller hear ing upon the cam-surfaces of the dog and toward its pivot, apivoted lever having Vibratory connection with the pump-rod and having arms embracing the clog, and set-screws extending through said arms, whereby the slack or lost motion between the arms and the dog may be regulated, substantially as cle- 1o scribed.

JOHN DOHERTY.

Witnesses:

JOHN A. HIGLEY, JENNIE E. NILAND. 

